Proper insulation in up-to-date water heaters is extremely important to both protect the end user and to reduce heat losses from the water heater. Many different methods have been used to insulate the walls of a water heater. Most of these methods involve the injection of foam material between the inner tank and the outer shell. The foam material, however, does not generally reach the bottom of the water heater resulting in significant heat loss in this area.
Suggestions have been made to provide insulation means, internally of, and at the bottom of the water heater. According to one suggestion the water heater is placed atop a bag-like insulation member which has shape change characteristics to conform to the bottom of the water heater. This type of bag, however, does not guarantee a positive fit to the bottom of the inner tank, and may further provide an improper seat for the tank so that it does not sit perfectly up-right within the water heater.
According to a further suggested design, a rigid insulation member having a u-shape configuration is seated immediately beneath the inner tank with the walls of the insulation member extending upwardly between the tank and the shell. This type of design, however, does not fit with the conventional inner tank design where the base of the tank is upwardly convex, furthermore, the u-shaped rigid insulation member described above may once again not provide a proper seat for the tank where the insulation member, typically made of foam, is relatively thick where it meets the lower tank edge, giving rise to a possible collapse of the foam material with a resultant tilting of the tank within the outer shell.
Presently available water heater insulation members make it very difficult to ground the tank to the shell which is necessary in an electric water heater.